Old thread, but i have a similar situation. Server was in storage for several years while i was abroad. Just fired it up but my USB has been damaged. I have the pro.key file and one back up file ldlinux.sys. I don't know which drive is the Parity. The two biggest drives are both 3 gigs. Think I'm running (was running 4.7). It's been awhile, it had Docker on it and a bunch of cool new stuff at the time . (maybe it was v5.0).
Thanks for any advice. I'm off to look at old photos to see if i have a pic of the old setup.